Today patients with cerebral aneurysms face a difficult choice: brain surgery or a less proven alternative

Think of it as a blood vessel in the brain that weakens like an old inner tube, develops a blister and eventually pops, spilling large quantities of blood into the skull. That, in a nutshell, is what doctors call a ruptured cerebral aneurysm. What it feels like is the worst headache of your life. My patients have described it as a "thunderclap" in the head followed by blinding pain, nausea and vomiting. They can't look at bright lights. Their necks get stiff. Confusion sets in. Half the people who suffer through one don't live to describe it.